AUSTIN -- Miles and miles of Texas highway will soon see speed limit increases following Thursday’s Texas Transportation Commission action approving 75 mph designations for close to 1,500 miles of interstate.

The speed limit changes span 60 Texas counties making it the largest conversion since a new law was passed last year. The 82nd Texas Legislature passed and the Governor signed House Bill 1353 which allows the Texas Department of Transportation (TxDOT) to establish 75 mph speed limits on Texas highways providing speed studies show it can be done safely.

TxDOT recommended to the Commission that speed limits be raised on segments of I-10, I-20, I-27, I-30, I-35, I-37, I-40, I-44 and I-45 after engineering studies showed that higher speeds could be posted safely.

Motorists must continue to travel at the posted speed until new signs are installed, said Rawson.

"The new speed limit is not official until the signs go up," she added.

TxDOT studies of speeds on U.S. highways, state highways, farm-to-market and ranch-to-market roads are still under way.